B12 deficiency again !

I would like some advice please, about 10 years ago I was diagnosed with B12 deficiency and subsequently had the injections for it. After having the injections for approximately 3-4 years the doctor stated my B12 levels were fine. Gradually over the years approximately 3 years in total I have felt worse and worse, I went for blood tests again to be told they were fine. Two weeks ago I went for more blood tests and they came back low again ! I basically had to beg for the injections stating my life consisted of going to work and on my days off incapable of doing anything. Please could I have some information about whether or not my injections should of been stopped ? As I feel myself they shouldn't have been. Thank you in advance.

9 Replies

  • You are quite right Chelle - your injections should never have been stopped. It seems to be a common misconception that high serum B12 levels after injections are proof that deficiency no longer exists.

    Here is the latest BMJ research document, supported by many research papers. It tells GP (bottom of page 4 under, "How is response to treatment assessed") :

    "Cobalamin and transcobalamin levels are not helpful because they increase with vitamin B12 influx regardless of the effectiveness of treatment and retesting is not usually required".

    In other words, once b12 treatment is started, the serum test results are not reflective of how effective the treatment is as they do not measure whether the B12 is absorbed into the tissues - it is the clinical condition of the patient that matters....

    BCSH guidelines also confirm this.


    Cmim/BMJ document. " Summary:

    * Vitamin B12 deficiency is a common but serious condition

    * Clinical presentation may not be obvious thus leading to complex issues around diagnosis and treatment.

    * There is no ideal test to define deficiency and therefore the clinical condition of the patient is of utmost importance."

    * There is evidence that new techniques, such as measurement of holotranscobalamin and methylmalonic acid levels seem useful in more accurately defining deficiency.

    * If clinical features suggest deficiency, then it is important to treat patients to avoid neurological impairment even if there may be discordance between test results and clinical features.

    Severe deficiency shows evidence of bone marrow suppression, clear evidence of neurological features and risk of cardiomyopathy.

    *It is important to recognise that clinical features of deficiency can manifest without anaemia and also without low serum vitamin B12 levels. In these cases, treatment should still be given without delay."

  • Thank you for this information, I will read the document attached. I hope I can explain this to my doctor adequately as they informed me that after the initial injections they would test my blood again to see if it was normal, I'm presuming to stop the injections once more !

  • I, personally, would print the document and mark the section concerned.

    Just recently, I had to mark a page from a BMA book on hypothyroidism when my GP wanted to reduce thyroid medication on the basis of unreliable test results - she was fine about it and there were no further attempts to dispute the dose.....

    Hope all goes well for you

  • The rather nice paper from the BMJ, what Polaris has linked to, also contains this bit that yuour doctor needs to make a note of:

    "Prescribe lifelong maintenance parenteral vitamin B12 treatment..."

    Especially that word 'lifelong'.

  • You became deficient in the first place because you had an absorption problem which meant that your ileum wasn't absorbing B12 efficiently. 99% of your B12 is absorbed through the ileum

    The body is quite efficient at recycling B12 - storing it in the liver, and then releasing it in bile when needed into the ileum where it is reabsorbed into the blood.

    However, if you have an absorption problem then that process is like using a bucket with a huge hole in it as very little of the 'recycled' B12 is actually going to be reabsorbed. So, it is only going to be a matter of time before you become deficient again, which is why you need supplementation for life.

    The NICE guidelines state that testing after treatment starts isn't necessary (though reality is that low tests will indicate that your kidneys are very efficient at removing excess B12 from your blood and you need injections more frequently).

  • I think Martyn Hooper, the chair of the PAS would be interested in hearing about your injections being cancelled and your subsequent deterioration. Sadly if you look at his blog you will see you are not alone in having injections stopped. In some cases the PAS is able to intervene.



    01656 769 717

    Office open 8am till 2pm

    If you leave a message they will get back to you within a few days.

    His latest book may be of interest to you and your GP. I gave a copy to my GP. It is up to date and mentions the BCSH Cobalamin Guidelines

    "What You Should Know About Pernicious Anaemia and Vitamin B12 Deficiency" by Martyn Hooper"

    Useful link if unhappy about treatment. Ideas for writing to Gps


    If you have time, reading some of the other threads on this forum may give you other helpful info.



  • Thank you for your assistance, I'm feeling more positive from everyone's responses as I don't feel so alone, and feel like im actually being listened to instead of being ignored and told I'm fine when actually I feel dreadful.

  • I am appalled that GP's are still doing this, stopping injections, when they are needed for life! Lots of good advice from everyone else on here, nothing I can add, except good luck on getting it sorted! Best wishes MariLiz

  • Proper treatment of B12 deficiency is worth fighting for because the consequence of inadequate or no treatment is potentially severe permanent neurological damage.

    I was forced to self treat as I was unable to get treatment from NHS. I had years of very gradual deterioration and suspect that if I had not started to self treat I might be starting to show signs of dementia and spinal cord degeneration

    "about 10 years ago I was diagnosed with B12 deficiency and subsequently had the injections for it"

    Do you mind me asking what the GPs thought was causing your B12 deficiency?

    Did they consider the possibility of PA (Pernicious Anaemia)?

    Have you ever had an IFA (Intrinsic Factor Antibody) test? It is still possible to have PA if the IFA test is negative.


    There are other causes of B12 defic besides PA.


    Other useful links/books etc

    "Could It Be B12" by Sally Pacholok and JJ. Stuart






    "I went for blood tests again to be told they were fine"

    In my opinion, the most important thing I have learnt from many years of being ill is to always get paper copies of blood test results as what I was told over the phone or even face to face was not always what was on the paper copies. Most surgeries will charge for making copies.

    I pay particular attention to folate, ferritin, B12 and Full Blood Count (FBC). There can be very useful clues on the FBC. I look at MCV and MCH. High MCH and high MCV can indicate the possibility of macrocytosis (enlarged red blood cells). Macrocytosis is sometimes found in those who are B12 deficient but not always.

    Low B12 and/or low folate can make red blood cells larger( macrocytosis). Low iron can make red blood cells smaller (microcytosis). A patient who has both low B12 and/or low folate plus low iron may have red blood cells that appear to be "normal" size. Macrocytosis due to low B12/folate can be masked by low iron. A GP might miss problems in a patient who has both conditions.

    A blood smear aka blood film might be helpful in identifying both low iron and low B12/low folate as it might show both macrocytic and microcytic cells in the same sample. B12 deficiency can cause hypersegmented neutrophils which might show up in a blood film/smear. Blood smears are mentioned in the BCSH Cobalamin and Folate guidelines.



    I am not a medic just a patient who has struggled to get a diagnosis and wants people to have useful info.

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